NTB: BWD Link Recovery
The BWD NTB device will drop the link if an error is encountered on the
point-to-point PCI bridge. The link will stay down until all errors are
cleared and the link is re-established. On link down, check to see if
the error is detected, if so do the necessary housekeeping to try and
recover from the error and reestablish the link.
There is a potential race between the 2 NTB devices recovering at the
same time. If the times are synchronized, the link will not recover and the
driver will be stuck in this loop forever. Add a random interval to the
recovery time to prevent this race.
Signed-off-by: Jon Mason <jon.mason@intel.com>
diff --git a/drivers/ntb/ntb_regs.h b/drivers/ntb/ntb_regs.h
index 4ddc590..03a66ef 100644
--- a/drivers/ntb/ntb_regs.h
+++ b/drivers/ntb/ntb_regs.h
@@ -115,6 +115,7 @@
#define BWD_MBAR45_OFFSET 0xb020
#define BWD_DEVCTRL_OFFSET 0xb048
#define BWD_LINK_STATUS_OFFSET 0xb052
+#define BWD_ERRCORSTS_OFFSET 0xb110
#define BWD_SBAR2XLAT_OFFSET 0x0008
#define BWD_SBAR4XLAT_OFFSET 0x0010
@@ -132,6 +133,20 @@
#define BWD_B2B_SPADSEMA_OFFSET 0x80c0
#define BWD_B2B_STKYSPAD_OFFSET 0x80c4
+#define BWD_MODPHY_PCSREG4 0x1c004
+#define BWD_MODPHY_PCSREG6 0x1c006
+
+#define BWD_IP_BASE 0xC000
+#define BWD_DESKEWSTS_OFFSET (BWD_IP_BASE + 0x3024)
+#define BWD_LTSSMERRSTS0_OFFSET (BWD_IP_BASE + 0x3180)
+#define BWD_LTSSMSTATEJMP_OFFSET (BWD_IP_BASE + 0x3040)
+#define BWD_IBSTERRRCRVSTS0_OFFSET (BWD_IP_BASE + 0x3324)
+
+#define BWD_DESKEWSTS_DBERR (1 << 15)
+#define BWD_LTSSMERRSTS0_UNEXPECTEDEI (1 << 20)
+#define BWD_LTSSMSTATEJMP_FORCEDETECT (1 << 2)
+#define BWD_IBIST_ERR_OFLOW 0x7FFF7FFF
+
#define NTB_CNTL_BAR23_SNOOP (1 << 2)
#define NTB_CNTL_BAR45_SNOOP (1 << 6)
#define BWD_CNTL_LINK_DOWN (1 << 16)